Growing indeterminate tomato varieties in the containers is possible, although you have to keep these tips in mind to enjoy good results.
First, choose the right containers. They must be at least 15 x 20'' and 5 gallons, but the larger, the better. Why? Indeterminate tomatoes grow up to 8-10 feet and can have their roots long up to 6 feet. The more soil you provide, the bigger they can get, and more fruits you can expect.
Porous containers absorb water, so avoid keeping them outdoors during the winter, because they can break when soaked and frozen. Avoid keeping black containers in the full sun, because the soil can heat too much then.
Choose a self watering container, or you will have to irrigate your tomato plants all the time. When the water escapes from the bottom of the container, the soil has to soak it back.
Make sure, that the container has enough drainage holes at the bottom. Put a large saucer underneath it, to prevent the water from running all over your patio.
Put a few rocks on the bottom of the container, to make it more stable. You don't want it to collapse, when your plants have grown tall and there's wind. Use a soil-less, peat based mix combined with compost, as your tomatoes need to grow in a well-drained medium, which is rich in nutrients.
Plant the seedlings, after you strip the bottom leaves from the veggies. Apply some mulch on the surface (leaves, bark, etc.) to retain moisture, but make sure, that it never touches the stems.
You need a strong support and cages tend to be too small for indeterminate varieties. Use the tall stakes, as tomato plants would overgrow the typical ones. A trellis makes the practical choice as well.
You can stretch the support between the containers, attach the vines to it and have them growing horizontally. This solution takes more space, but you can reach for the fruits easily.
Prune the suckers, so that the plant has no more than four vines. More would be too difficult to handle and the tomato would yield less fruits.
While indeterminate tomatoes in containers grow smaller, than in the ground, you can enjoy a great harvest, when you follow these tips. Choose determinate types of tomato plants, if you wish to use smaller pots. Which variety did you include in your gardening plan this year?